Concept/Vocabulary
Word
Definition
Circulatory System
The body system that circulate blood through the body, consisting of the heart, blood vessels, and blood that
circulates blood throughout the body. It delivers nutrients and other essential materials to cells, and removes waste
products. Also called cardiovascular system.
Digestive System
The structures in the body that work together to transform the energy and materials in food into forms the body can
use. It is a system responsible for the ingestion, digestion, and absorption of food.
Excretory system
It is the body system that removes excess, unnecessary or dangerous materials from the body. It helps to maintain
homeostasis within the organism and prevent damage to the body.
Homeostasis
The mechanism which regulates the body's internal condition. All body systems work together to maintain
homeostasis to ensure certain chemical compositions of body fluids, so as to maintain health and functioning,
regardless of outside conditions. The body maintains homeostasis by monitoring its internal conditions and
responding appropriately when these conditions deviate from their optimal state. The maintenance of a steady body
temperature in warm-temperature involves such mechanisms as sweating when the internal temperature becomes
excessive and shivering to produce heat, as well as the generation of heat through metabolic processes when the
internal temperature falls too low.
Reproductive
System
The system of organs involved with animal and human reproduction, especially sexual reproduction. The
reproductive system consists mainly of the ovaries, fallopian tubes, uterus, and vagina in females and the testes,
sperm ducts, and penis in males.
Respiratory System
A system that interacts with the environment and with other body systems to bring oxygen to the body and remove
carbon dioxide
Alveoli
Any of the tiny air-filled sacs arranged in clusters in the lungs, in which the exchange of oxygen and carbon
dioxide takes place.
Bronchi
Either of the two main branches of the trachea that lead to the lungs, where they divide into smaller branches.
Diaphragm
A dome-shaped structure made up of muscle and connective tissue that separates the abdominal cavity from the chest
and either draws air into the lungs or forces air out of them.
Gas exchange
The diffusion of gases from an area of higher concentration to an area of lower concentration, especially the
exchange of oxygen and carbon dioxide between an organism and its environment.
Lungs
A pair of organs, the principal parts of the respiratory system, at the front of the cavity of the chest in which the lungs
transfer oxygen from the air into the blood, while carbon dioxide is removed from the blood and exhaled.
Trachea
The tube connecting the mouth to the bronchial tubes that carries air to the lungs; also called the windpipe.
Artery
Any of the blood vessels that carry oxygenated blood away from the heart to the body's cells, tissues, and organs.
Atrium
A chamber of the heart that receives blood from the veins and forces it by muscular contraction into a ventricle.
Blood Pressure
The pressure of the blood in the vessels, especially the arteries, as it circulates through the body.
Capillary
Tiny blood vessels that connect the smallest arteries to the smallest
veins exchanging oxygen, metabolic waste products, and carbon dioxide between blood and tissue cells.
Heart
The hollow, 4 chamber muscular organ that pumps blood through the body by contracting and relaxing.
Hemoglobin
An iron-containing protein that binds chemically to oxygen molecules, makes up most of red blood cells.
Plasma
The clear, yellowish fluid portion of blood, lymph, or intramuscular fluid in which cells are suspended.
Platelets
Small, round cell fragments containing no nuclei that are found in the blood and help in the clotting of blood.
Red Blood Cell
A disk-shaped cell in the blood that contains hemoglobin, lacks a nucleus, and transports oxygen and carbon
dioxide to and from the tissues.
Valve
A flap like structure in a hollow organ, such as the heart, that controls the one-way passage of fluid through that
organ.
Vein
Any of the blood vessels that carry deoxygenated blood toward the heart from the body's cells, tissues, and organs.
Ventricle
A chamber of the heart that receives blood from one or more atria and pumps it by muscular contraction into
the arteries.
White Blood Cell
Colorless cells in the blood that help combat infection.